ARLINGTON -- The Rangers placed reliever Eddie Guardado on the 15-day disabled list and called up reliever Willie Eyre from Triple-A Oklahoma City before Wednesday's game against the Twins.
The move was retroactive to Saturday, meaning Guardado is eligible to return August 30. He is out with left knee inflammation.
Eyre is in uniform and available for Wednesday's game. He is 0-0 with a 4.91 ERA over six relief appearances and three stints with the Rangers this season. Eyre was also with the club from April 15-22, June 26-28 and July 20-27.
Guardado, 38, is 1-2 with a 4.32 ERA over 33 1/3 innings for the Rangers this season. He recently made the 900th appearance of his career but hasn't pitched well of late.
"It's hurt for a little while -- about four years," Guardado said with a laugh. "I've played with it a long time. The older you get the worse it gets. If it doesn't get better, it's got to be fixed."
Guardado said he will have a cortisone shot on Wednesday and also said he doesn't expect to be out much longer than the 15 days.
Guardado allowed three home runs in his past six games, including a game-tying, two-run home run against the Red Sox on Friday and a game-winning shot on August 8 against the Angels.
Over his past six games, he has a 9.82 ERA (six runs -- four earned -- over 3 2/3 innings pitched). Guardado joined the club after coming into Spring Training as a non-roster invitee and has played the entire season, allowing a run in 10 of his 42 appearances.
Eyre started the season on the disabled list with a strained right groin. He last pitched in the Major Leagues on July 26 against the Royals, when he allowed one run over one inning of work.
Eyre produced 2 1/3 scoreless innings and made 30 pitches at Triple-A on Monday. While with the RedHawks, he was 0-0 with one save and a 2.45 ERA.
Daniel Paulling is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.